1.2.1 Abstract: This data set is a file of the WGS 84 EGM96, fully normalized, earth
gravity (geopotential) coefficients, complete to degree (n) and order (m) 360. These
spherical harmonic coefficients are used in Clenshaw summation numerical algorithms or FFT
algorithms to compute the following gravimetric quantities: point gravity anomalies, point
geoid heights, point N-S or E-W components of the deflection of the vertical, point total
deflection of the vertical, point radial component of the gravity disturbance vector, and
point N-S or E-W component of the gravity disturbance vector. Mean gravimetric quantities
can also be calculated from the EGM96 geopotential coefficients. The WGS 84 EGM96 model is
based on the WGS 84 ellipsoid, and the coefficients are calculated from a worldwide
database of 30 minute mean free air gravity anomalies plus satellite tracking data and
direct altimetry.

1.2.2 Purpose: The WGS 84 EGM96 coefficients are required in the spherical harmonic
equations that are used to calculate the gravimetric quantities listed above. The data
from these calculations are used primarily by the DoD and their contractors to provide
long wavelength models of the Earth's gravity field and geoid for various weapon systems.

1.14 Cross Reference: WGS 84 EGM96 (n=m=360) model is used as a part of the
service titled, Geodetic Quantities from Spherical Harmonics, which is also provided by
NGA Geospatial Sciences Division. Please check the metadata listing for this service.

6.4.2.2.2.4 Compatibility Information: DOS Compatible for floppy, other media are
created using UNIX commands.

6.4.3 Fees: No Fee

6.4.5 Turnaround: Less than two days

6.5 Custom Order Process: Customers must contact the Identification Information
Section Point of Contact. The WGS 84 EGM96 (n=m=360) model can be ordered as a separate
product in the form of the EGM96 geopotential coefficients with associated worldwide 15
minute geoid height grid. Interpolation and harmonic synthesis software are also
available.

6.6 Technical Prerequisites: The user should have a familiarity with geographic
information, e.g. latitude and longitude, and with MS-DOS language. Knowledge of Fortran
77 would be helpful but not mandatory.